I had to put down my 12 year old Westie yesterday. One of the hardest things I've had to do. We have 2 small children and he'd nipped at each one of the kids and bitten me several times from accidentally waking him up. We discussed putting him down or re-homing him, but the vet talked us out of it several years ago when he first showed signs of aggression. Re-homing aggressive dogs is difficult, so we decided to be careful not to let the kids play with him, and try to make it work. He never had another incident with the kids, but over the last 3 weeks he bit my wife's foot, and my hand bad enough to draw blood, both times unprovoked. Two nights ago he was laying in the recliner next to the recliner I was sitting in and when I got up the remote fell in front of his chair. As I bent to pick it up he bit my face. More precisely just above my left eye. Luckily I shut my eye in time and it only put a small cut on my eyelid and caused some bruising. Very scary and I knew that was it. He had to be put down. So sad.
After reading that paragraph it sounds like a no brainer. Which is what my wife and I keep telling ourselves. What makes it so hard is he physically had another year or two in him. He still had good vision, hearing, could easily jump up on the furniture, still occasionally chased rabbits and birds and ran with ease. The vet thought he may have developed a tumor and that was causing discomfort, which caused the aggressive behavior. He said they could put him through all the tests and MRI's to see, but a dog his age wouldn't gain much in terms of comfort and prolonging his life for what it would all cost. (He told us this before he bit my face). After the last bite, we knew it was time and what we had to do. I partially blame myself for getting my face within striking distance and keep running the last 2 days through my mind. So painful. He gave us 10 great years and 2 years of gradually getting more and more aggressive. I dreaded having to put him down on bad terms once he started biting. I'm just glad he bit me and not one of my kids and that my eye injury wasn't serious. RIP Ferris. Your infectious energy and playfulness will be sorely missed.